Sorry, no I didn't have to do any detecting. It sounds like you got that working though...
If you're working with a 1602 panel as well, did you try the other common addresses, just in case? ( 0x20 , 0x27 , 0x3F)
Also, make sure your contrast adjustment pot isn't all the way up or all the way down, it makes it impossible to see text. A good way to test if your board is talking to the panel is to turn off the backlight programmatically in setup().